The present invention(s) relates to expandable implants and tools for the insertion of such implants. More particularly, the invention(s) pertains to an expandable spinal implant having opposed plates, which are expandable via the interaction between a wedge member and ramped surfaces included on the plates. An insertion instrument used for implantation of the implant, and methods of utilizing the same, are also disclosed.
Common spinal maladies, such as degeneration of an intervertebral disc of the spine (commonly referred to as Degenerative Disc Disease), spondylosis, spinal stenosis, disc herniation, retrolisthesis, discogenic back pain, or other like conditions may result in substantial pain and discomfort for a patient. Frequently, conditions of this type are treated through surgical intervention, which may include replacing or removing a portion or all of the affected disc(s) and fusing the associated vertebrae through the use of an implant or other like device. In particular applications, adjacent vertebral bodies may be fused via an implant, through screw arrangements, and/or by using bone graft material to secure the vertebrae in a fixed state and promote bone growth between the vertebrae.
In replacing a diseased intervertebral disc(s) and effecting fusion, it may also be necessary to ensure that proper spacing is maintained between the vertebral bodies. Stated differently, once the implant or other like device is situated between adjacent vertebrae, the implant or device should adequately recreate the spacing previously maintained via the excised intervertebral disc (e.g., in its natural condition). Various expandable implants have been proposed for this purpose. As such, it is possible for a surgeon to adjust the height of particular intervertebral implants to intra-operatively tailor the implant height to match the natural spacing between vertebrae, or any desired implant height. This may reduce the number of different implants needed to accommodate the anatomical confines of different patients.
Various anatomical considerations are also present when implanting an implant between adjacent vertebrae and, for example, affecting fusion. In particular, certain areas of the spine (e.g., the lumbar and cervical areas) may include vertebrae that are, in their natural state, at an angle to one another. This natural angle is created by the lordosis or inward curvature of the spine at the particular location of the spine (lumbar/cervical). Thus, due to the naturally-occurring inward curvature of the spine at certain sections, adjacent vertebrae are at an angle to one another, which may be taken into account in certain applications.
Although several versions of expandable intervertebral implants are known, as detailed above, the need for an improved expandable implant remains.